Plate rubbing member for lithographic plate developing machine

ABSTRACT

A plate rubbing member for a lithographic plate developing machine which includes a core of tubular conformation. A plurality of spaced rods are secured to the outer periphery of the core and extend longitudinally thereof. The exterior surface of each rod is provided with a friction surface. A tubular member of yieldable absorbent material is sleeved over the core and the friction surfaces of the rods grip the inner periphery of the tubular member in a manner to prevent rotary and longitudinal movement of the tubular member relative to the core upon rotation and oscillation of the rubbing member. Disks on the rubbing member engageable with the terminals of the tubular member positively preclude the absorbent material from sliding back and forth on the core during oscillating movement of the rubbing member.

United States Patent Casson, Jr.

[ 51 Mar. 28, 1972 [72] lnventor: Edward A. Casson, Jr., Airpark Drive,

Easton, Md. 21601 F l July 28,1969

[21] Appl.No.: 845,446

[52] U.S. Cl ..29/129 [51] ..B21b 31/08 [58] Field of Search ..29/129,129.5, 130

[56] References Cited UNITED STATES PATENTS 3,152,387 10/1964 Macleod..29/129.5 X

52,153 l/l866 682,607 9/1901 2,280,125 4/1942 2,715,879 8/1955 2,871,7372/1959 3,447,221 6/1969 Odiorne ..29/130 X FOREIGN PATENTS ORAPPLICATIONS 951,240 3/1964 Great Britain ..29/129 1,059,659 11/1953France ..29/129.5

Primary Examiner-Alfred R. Guest Attorney-Shlesinger, Arkwright & Garvey[57] ABSTRACT A plate rubbing member for a lithographic plate developingmachine which includes a core of tubular conformation. A plurality ofspaced rods are secured to the outer periphery of the core and extendlongitudinally thereof. The exterior surface of each rod is providedwith a friction surface. A tubular member of yieldable absorbentmaterial is sleeved over the core and the friction surfaces of the rodsgrip the inner periphery of the tubular member in a manner to preventrotary and longitudinal movement of the tubular member rela tive to thecore upon rotation and oscillation of the rubbing member. Disks on therubbing member engageable with the terminals of the tubular memberpositively preclude the absorbent material from sliding back and forthon the core during oscillating movement of the rubbing member.

6 Claims, 5 Drawing Figures Patented March 28, 1972 INVENTOR.

EDWARD A. CASSON, JR.

PLATE RUBBING MEMBER FOR LITI-IOGRAPIIIC PLATE DEVELOPING MACHINEBACKGROUND AND OBJECTS In the developing machine forming the subjectmatter of my pending application Ser. No. 8 14,5 I6, filed Apr. 9, 1969,now US. Pat. No. 3,534,882, a salient feature of this machine is a platerubbing member which works up" an image on an exposed lithographicplate. For performing this function, the rubbing member includes acylindrical sponge which is rotated about its longitudinal axis whichlies parallel to the surface of the plate to be developed. The lowerportion of the rotating sponge passes through a pan of developingsolution to impregnate the sponge with the solution. The periphery ofthe sponge engages the exposed face of the lithographic plate to work upthe image and nonimage areas of the plate.

Since an absorbent and pliable material is used for contact with theplate, this material must be mounted on a solid core member in order tolend the desired stability to the roller operation. Also, the materialmust be readily removable from the core in order to permit replacementafter a period of use.

It is an object of this invention to provide a plate rubbing memberincluding a core on which is sleeved a yieldable and absorbent material,the core being so constructed to prevent relative rotation and/orlongitudinal movement of the absorbent material with respect to thecore.

Another object is to provide a'plate rubbing member of the characterdescribed, wherein the core is tubular and the outer periphery thereofis provided with a series of fixed, rodlike protuberances extendinglongitudinally of the core for engaging and gripping the inner peripheryof the absorbent material, the protuberances being provided withfriction surfaces throughout their lengths to positively precludelongitudinal movement of the absorbent material with respect to thecore.

A further object is to provide a developing roller which may beeconomically manufactured and which applies a uniform rubbing action toeach plate being developed.

Other objects will be manifest from the following description of thepresently preferred form of the present invention taken in conjunctionwiththe appended drawing.

DESCRIPTION OF FIGURES OF DRAWING FIG. 1 is an elevational view of theplate rubbing member of the present invention;

FIG. 2 is a perspective view of the'p'late rubbing member of the presentinvention, portions thereof being broken away to disclose details;

FIG. 3 is an enlarged end elevational view of the same;

FIG. 4 is a sectional view taken along the line 4--4 of FIG. 2, lookingin the direction ofthe arrows, and

FIG. 5 is a fragmentary, enlarged longitudinal sectional view of thecore forming a part of the present invention.

DETAILED DESCRIPTION-OF THE INVENTION The plate rubbing member of thepresent invention comprises a core generally designated 20'and a plateengaging portion designated 22.

Core 20 includes a tubular member 24 made of metal or any other suitablerigid material. Adjacent one terminal, the thickness of tubular member24-is reduced at 26 to provide a shoulder or abutment 28. A locatingslot 30 extends inwardly from the extreme terminal of one end of thetubular member to abutment 28 for rotatably mountingthe roller on adeveloping machine of the character described in my pending applicationSer. No. 8 l4,566.

It is a salient feature of the present invention to provide a pluralityof rodlike protuberances on the outer periphery of tubular member 24,the protuberances preferably comprising a series of rods 32 which arewelded or secured in any other suitable manner to member 24. If desired,the protuberances may, of course, be formed integrally with tubularmember 24 to provide a unitary core structure.

In accordance with the present invention, rods 32 are threaded at 34 toprovide a friction surface for purposes which will be hereinafter morefully set out.

Plate rubbing member 22 includes an absorbent, yieldable cylindricalmember 36, made of synthetic sponge or other suitable material which maybe sleeved over core 20. As shown to advantage in FIG. 4, rods 32 alongthe outer periphery of tubular member 24 engage the iriner periphery ofmember 36 in a manner to prevent relative rotational movement of member36 with respect to core 20.

Threads 34 of rods 32 also engage the inner periphery of member 36 in amanner to prevent longitudinal movement of member 22 with respect tocore 20.

In order to positively preclude any relative longitudinal movement ofmember 22 with respect to c'ore 20, end disks 38 are affixed by suitablemeans 40 to core 20, the disks being in contiguous engagement with theterminals of member 36 to confine the latter therebetween.

Although six rods are illustrated as applied to tubular member 24, anydesired number for carrying out the purposes of the present inventionmay be employed. Optimum results have been obtained with this number ofrods applied to a 2% inch diameter tube, on which a cylindrical spongemember of 5% inches in diameter has been sleeved.

With the device of the present invention, accidental displacement of theyieldable cylindrical member with respect to the core is obviated but,at the same time, replacement of the cylindrical member is readilyeffected.

What I claim is:

1. A plate rubbing member for a lithographic plate developing machine,including:

a. a core comprisinga tubular member,

I). a plurality of uniformly spaced rods secured to the outer peripheryof said tubular member,

c. said rods extending longitudinally of said tubular member,

d. the surface of said rods being threaded to provide a frictionsurface,

e. a cylindrical member of yieldable, absorbent material in sleevedengagement with said core,

f. said cylindrical member being engaged by said rods,

g; whereby upon rotation of longitudinal oscillation of the rubbingmember, said rods prevent relative rotation of the core with respect tothe cylindrical member, and the threaded surface of the rods preventsrelative longitudinal movement of said core with respect to thecylindrical member. 2 The plate rubbing member of claim 1, with theaddition of:'

a. retaining disks carried by said core and engageable with theterminals of said cylindrical member.

3; A plate rubbing member for a lithographic plate developing machineincluding:

a. a core comprising a tubular member,

b. a yieldable cylindrical member in sleeved engagement with said core,

c. a first means carried by said tubular member and frictionally engagedwith said yieldable member, for preventing relative rotational movementbetween said tubular and cylindrical members,

d. a second .means carried by said first means and frictionally engagedwith said yieldable cylindrical member for preventing relativelongitudinal movement between said tubular and cylindrical members, and

e. said secondmeans comprising a threadlike surface extendingtransversely of said first means, and substantially coextensive with thelength thereof;

4. The plate rubbing member of claim 3 wherein:

a. said first means comprises a plurality of rods secured to the' outerperiphery of said tubular member.

5". The plate rubbing member of claim 3 with the addition a.retaining-discs carried by said coreand engageable with the terminals ofsaid yieldable cylindrical member.

6. The plate rubbing member of claim 3, wherein: a. said yieldablecylindrical member is made of a material having the absorbent qualitiesof sponge.

1. A plate rubbing member for a lithographic plate developing machine,including: a. a core comprising a tubular member, b. a plurality ofuniformly spaced rods secured to the outer periphery of said tubularmember, c. said rods extending longitudinally of said tubular member, d.the surface of said rods being threaded to provide a friction surface,e. a cylindrical member of yieldable, absorbent material in sleevedengagement with said core, f. said cylindrical member being engaged bysaid rods, g. whereby upon rotation of longitudinal oscillation of therubbing member, said rods prevent relative rotation of the core withrespect to the cylindrical member, and the threaded surface of the rodsprevents relative longitudinal movement of said core with respect to thecylindrical member.
 2. The plate rubbing member of claim 1, with theaddition of: a. retaining disks carried by said core and engageable withthe terminals of said cylindrical member.
 3. A plate rubbing member fora lithographic plate developing machine including: a. a core comprisinga tubUlar member, b. a yieldable cylindrical member in sleevedengagement with said core, c. a first means carried by said tubularmember and frictionally engaged with said yieldable member, forpreventing relative rotational movement between said tubular andcylindrical members, d. a second means carried by said first means andfrictionally engaged with said yieldable cylindrical member forpreventing relative longitudinal movement between said tubular andcylindrical members, and e. said second means comprising a threadlikesurface extending transversely of said first means, and substantiallycoextensive with the length thereof.
 4. The plate rubbing member ofclaim 3 wherein: a. said first means comprises a plurality of rodssecured to the outer periphery of said tubular member.
 5. The platerubbing member of claim 3, with the addition of: a. retaining discscarried by said core and engageable with the terminals of said yieldablecylindrical member.
 6. The plate rubbing member of claim 3, wherein: a.said yieldable cylindrical member is made of a material having theabsorbent qualities of sponge.